Milan's general aviation traffic lands just eight kilometres from the cathedral, on the Bresso airstrip, today the base of the Aero Club Milano; but during the war that same strip was used to test military aircraft built by Breda, and on the thirtieth of April 1944 an Allied bombing raid aimed at the airfield killed five people. Old doubts remain about the town's name: it may come from the Celtic brig, hill or stronghold, from the name of the French region of Bresse, or from a Germanic landowner called Berizzo. Its farming vocation is more certain, and left its mark on the town's coat of arms: in 1750 the Theresian census counted twenty-eight and a half mulberry trees per pertica in Bresso, against a Lombard average of seven, more than four times the norm, the fruit of a 1470 edict by Galeazzo Maria Sforza requiring rows of mulberries to be planted in the countryside.
After the war, in 1942, the engineer Renzo Rivolta turned the eighteenth-century Patellani villa, which he had bought in 1939, into the headquarters of his factory, Iso Rivolta: from those workshops came the Isetta and the Grifo, before the area, in 1969, became a public park named after Rivolta himself, its old workshops later converted into a museum. Today Bresso, entirely merged into the built-up area with Milan and Sesto San Giovanni, is the most densely populated municipality in Italy outside the province of Naples, and the small aircraft taking off from the runway offer a striking contrast with the dense residential fabric that surrounds it.